Background: Few studies have reported the use of toothbrushes as a reliable source of DNA for human or gender identification. The present systematic review with the available information was conducted to answer the focus question “Is a toothbrush a reliable source of DNA for human or gender identification?”. Methods: The keyword combination “Toothbrush” and “DNA” was used to search databases including MEDLINE, Scopus, and Web of Science along with a manual search of reference lists of relevant articles. Duplicates and irrelevant articles were excluded, and the remaining articles were fully read for the final selection of articles. The risk of bias of the included studies was evaluated using the Appraisal tool for Cross-Sectional Studies (AXIS tool). Results: Of the 130 articles obtained, 122 duplicates or irrelevant articles were eliminated. Following the full-text reading of eight articles, five articles were selected based on eligibility criteria. The five studies reported that a toothbrush is a good source of DNA irrespective of the time interval. In a few studies some samples were not sufficient for complete DNA profiling due to factors such as the method of DNA extraction. Conclusion: Although a toothbrush is an excellent source of DNA for human and gender identification, future studies with a larger sample size, appropriate control group, and standardized technique of DNA extraction need to be conducted. Additionally, factors influencing the quantity and quality of DNA in toothbrushes need to be determined with standardized techniques.

Odontomas are the most commonly occurring odontogenic tumors, which are considered by many to be hamartomas rather than neoplasms. These clinically asymptomatic tumors are classified into complex and compound odontomas. They are usually discovered in radiographs and rarely cause bony expansion or infection. This paper discusses a case report of a complex odontoma exhibiting all the structural features and defects of enamel, dentine, and cementum in succession, with an overview on its etiology.

To explore the viability of used toothbrush as a source of gene expression and comparison of the same among tobacco, alcohol, diabetic and hypertensive subjects. Fourteen subjects with a history of type 2 diabetes mellitus (T2DM) and hypertension were allocated to Group I, 14 subjects with tobacco and alcohol habits allocated to Group II and 14 healthy subjects allocated to Group III. Genetic materials retrieved from the used toothbrush of the study subjects were assessed for genetic expression of cyclin-dependent kinase 4 (CDK4), Bcl-2-like protein 4 (BAX), cyclin-dependent kinase inhibitor 2A (CDKN2A), B-cell lymphoma 2 (BCL2), G-protein beta-3 (GNB3), and subunit gene and transcription factor 7-like 2 (TCF7L2) by polymerase chain reaction (PCR). BAX gene showed reduced expression in tobacco and alcohol users (p=0.0497). BCL2, CDK4, and GNB3 showed no significant difference in expression in both the groups and with control. CDKN2A was expressed at a lower level in Group I and II participants. TCF7L2 showed higher expression in Group 2 participants (p=0.001). The study concluded that used toothbrush is a reliable source for genetic expression. There was no difference in BCL2, CDK4, and GNB3 gene expression between subjects with systemic disease, adverse habits and healthy controls. There is a downregulation of BAX and upregulation of TCF7L2 gene in subjects with adverse habits.